This invention relates to processes for filtering. In one of its aspects this invention relates to coalescing oil droplets dispersed in a water phase. In another of its aspects, this invention relates to a method for separating dispersions of oil in water. In yet another of its aspects this invention relates to oleophilic filtering media.
In one of its concepts this invention relates to the agglomeration of oil droplets dispersed in a water phase by passage of a mixture of oil droplets in water through a filtering medium which will agglomerate the oil droplets into masses of oil of sufficient size to facilitate separation of the oil and water.
Ballast water in water tankers and bilge water from oil fired ships are frequently contaminated with residual oil which may form a stable emulsion. In the past such waste water was discharged directly into the ocean or seaways. Our realization of the importance of the prevention of environmental pollution has caused the seeking of ways to substantially reduce or eliminate the discharge of oily residue from ships.
One of the methods through which a cleaner environment has been sought is by filtering oily water residue before discharge of the water into the environment. Filter units through which discharged water is pumped have been installed in a number of ships. Since a filtering system is no better than the filtering medium used in the system considerable work has been done to establish workable media for removing dispersed oil from water. Experimental data, evaluated visually, has shown that oleophilic, nonwoven fabric has excellent properties for coalescing dispersed oil from water mixtures.
It is therefore an object of this invention to provide filtering media for the removal of oil dispersed in a water phase. It is another object of this invention to provide a method for agglomerating or coalescing oil dispersed in water mixtures. It is a further object of this invention to provide a method for separating oil and water from an oil dispersion in a water phase.
Other aspects, objects and the advantages of this invention will be apparent to one skilled in the art upon studying the specification, drawing and the appended claims.